Your Mac includes a built-in Dictionary app (in the Applications folder) that allows you to search through detailed entries for thousands of words and phrases. You can search in the app itself or use Spotlight. You can even browse Wikipedia entries right from within the Dictionary app.

When you're trying to open Terminal from macOS Spotlight, but Spotlight only gives you the Dictionary definition for Terminal. Sweet thanks.

There’s a simple text file that contains the words you add to the dictionary. Today we’ll cover an easy way to add and remove words from that custom dictionary file if you only have one or a few to add or remove. We’ll also show you how to edit the custom dictionary file directly, which is useful if you want to add and remove a bunch of words in one go.

Add Words to the Built-In Dictionary on Mac

A word of warning before we show you how to add a word to the dictionary: this method does not always work. We could not add MakeUseOf to the dictionary using this method. I don’t know why. It is an important word and it’s not already in the Dictionary app.

If you find you cannot add your word this way, don’t worry! There’s an equally easy way to add it later in this article.

To add a word to the built-in dictionary on your Mac, open TextEdit and type the word exactly as you want it to appear in the dictionary. Do not add a space after the word.

No matter where your allegiances lie with PC vs Mac, it's an indisputable fact that "Learn Spelling" is the Mac's best feature.

Next, select the whole word, right-click or Control + click on it, and select Learn Spelling from the popup menu.

Repeat for each word you want to add to the dictionary. Once you’re done, close the TextEdit document. You don’t need to save the document. The words have been added to and saved in the dictionary file.

Now, the word you added won’t be flagged as misspelled with the red squiggly underline the next time you type it.

Remove Words From the Built-In Dictionary on Mac

If you made a typo in a word you added to the dictionary, or you just want to remove a word you don’t use anymore, you can easily remove the word. The procedure is like adding a word to the dictionary.

Note: This method of removing a word from the dictionary only works for words you added yourself, not words included in the dictionary by default.

To remove a word from the built-in dictionary, open new TextEdit document and type the word you want to remove. Again, do not add a space after the word.

Next, select the whole word, right-click or Control + Click on it, and select Unlearn Spelling from the popup menu.

Repeat for each word you want to remove from the dictionary. Once you’re done, close the TextEdit document. You don’t need to save the document. The words have been removed from the dictionary file and the file is automatically saved.

Add, Remove, and Edit Words in Your Custom Word List

If you have more than just a few words you want to add or remove, you can edit the dictionary file directly.

The custom word list you’ve been adding words to and removing words from is named LocalDictionary in your user Library folder. It’s a regular text file. To edit the LocalDictionary file, open a Finder window and look in your user folder for the Library folder.

The tilde symbol (~) stands for the Home folder. In our example, the Home folder is /Users/lorikaufman.

In the Spelling folder, right-click on the LocalDictionary file and go to Open With > TextEdit.app.

The LocalDictionary file opens in TextEdit. Each word appears on a separate line. You can edit these words, add more words, and delete words just like you would when editing any other text file.

Make sure you put each word on a separate line.

Go to File > Save or press command+s to save the LocalDictionary file.

Not All Apps Use the Built-In Dictionary

The built-in dictionary is available in most programs, the notable exceptions being Microsoft Word and Google Docs. If you add a word to the built-in dictionary and find that a program is still complaining about that word, that means the program has its own dictionary, and you’ll need to update that dictionary with the word you want to add.

The procedure for adding a word to the dictionary in other programs will vary. You might be able to add words to the dictionary as you do a spell check on a document, or you can check the Preferences or Settings for the program.

Were you able to add or remove words using the TextEdit method we mentioned? Do you prefer to edit the LocalDictionary file directly? Share your thoughts and experiences with us in the comments below.

Lori Kaufman is a freelance technical writer living in the Sacramento, CA area. She's a gadget and tech geek who loves to write how-to articles about a wide range of topics. Lori also loves reading mysteries, cross stitching, musical theatre, and Doctor Who. Connect with Lori on LinkedIn.